BaseProcessor.java

/**
 *
 */
package com.thinkbiganalytics.nifi.v2.common;

/*-
 * #%L
 * thinkbig-nifi-core-processors
 * %%
 * Copyright (C) 2017 ThinkBig Analytics
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */

import com.thinkbiganalytics.nifi.processor.AbstractNiFiProcessor;

import org.apache.nifi.components.PropertyDescriptor;
import org.apache.nifi.processor.ProcessorInitializationContext;
import org.apache.nifi.processor.Relationship;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

/**
 */
public abstract class BaseProcessor extends AbstractNiFiProcessor {

    private Set<Relationship> relationships;
    private List<PropertyDescriptor> properties;

    /* (non-Javadoc)
     * @see org.apache.nifi.processor.AbstractSessionFactoryProcessor#init(org.apache.nifi.processor.ProcessorInitializationContext)
     */
    @Override
    protected void init(final ProcessorInitializationContext context) {
        super.init(context);

        final Set<Relationship> relationships = new HashSet<>();
        addRelationships(relationships);
        this.relationships = Collections.unmodifiableSet(relationships);

        final List<PropertyDescriptor> properties = new ArrayList<>();
        addProperties(properties);
        this.properties = Collections.unmodifiableList(properties);
    }

    /* (non-Javadoc)
     * @see org.apache.nifi.processor.AbstractSessionFactoryProcessor#getRelationships()
     */
    @Override
    public Set<Relationship> getRelationships() {
        return relationships;
    }

    /* (non-Javadoc)
     * @see org.apache.nifi.components.AbstractConfigurableComponent#getSupportedPropertyDescriptors()
     */
    @Override
    protected List<PropertyDescriptor> getSupportedPropertyDescriptors() {
        return properties;
    }

    /**
     * Convenience method for collecting the properties that the processor will support.
     * Subclasses should call super.addProperties(list) before adding additional properties.
     *
     * @param props the list to which is added this processor's properties
     */
    protected void addProperties(List<PropertyDescriptor> list) {
    }

    /**
     * Convenience method for collecting the relationships that the processor will support.
     * Subclasses should call super.addRelationship(set) before adding additional relationships.
     *
     * @param props the set to which is added this processor's relationships
     */
    protected void addRelationships(Set<Relationship> set) {
    }
}